If your partner has cheated and has gone through great lengths to lie and cover it up, there is a serious problem there. For instance, you found out somehow of your partner's infidelity and he/she gave you heartfelt apologizes swearing to never cheat or do anything else to ever hurt you ever again. You forgive and take him/her back. You soon discover that your partner has cheated again, even after all of that making up, begging and crying he/she did to help rebuild your trust. This is a clear sign that there are problems in the relationship, perhaps the other person possesses more personality traits, skills, physical attributes, etc. than you. Perhaps, your partner is not worthy of trust but continuously persuade you to believe that you are the one when you CLEARLY are NOT.

Taking someone back after the discovery of cheating once is extremely difficult and takes work on both party's behalf. Surely there were lies told, apologizes made, tears cried, and hearts broken. These things will always remain in the back of your mind whether you chose to act on your feelings or not. Most relationships never fully recover from infidelity because it is extremely damaging. Without 100% full trust in your partner, the relationship is not worth having. The replays of events, stress, wild imaginations, constant lines of questions and investigations wears one down over time.

The best thing to do in a situation where there's proof of cheating, especially multiple cheating incidents, is to walk away. Staying does not prove your love for your partner; it only proves your lack of self-esteem and lack of self-worth. You will look back later and regret not leaving sooner.